Fog harvesting to provide poor with water

A study is being done to see if Mpumalanga’s poorest communities can harvest fog as a vital water source.

The national Department of Rural Development and Land Reform plans to conduct a pilot project next year with the hope of rolling out fog harvesting to communities along the province’s eastern escarpment.

“If the pilot project yields positive results, we will consider a large scale roll-out to feed into local water distribution networks,” said department spokesman Eddie Mohoebi on Monday.

It is hoped the project will alleviate water shortages in South Africa, which is one of 30 countries with the worst water scarcity in the world. The country’s average annual rainfall of 450mm is nearly half of the global average of 860mm per year.

Communities in Cabazane village near Mount Ayliff in the Eastern Cape and Thohoyandou in Limpopo are already harvesting fog and providing clean water for their basic needs.

Fog is caught by a 40 square metre net made of stainless mesh co-knitted with a poly material attached to six-metre-high wooden poles.

Gutters, attached to the bottom of the net, catch the water droplets and lead it down into reservoirs.

The pilot project in Mpumalanga aims to produce 5 000 litres to 15 000 litres of water per day through fog harvesting.

According to statistics from the South African Weather Service (SAWS), Mpumalanga’s weather stations recorded 225 days of fog in 2010. It is the highest number of fog days for all provinces in South Africa.

SAWS senior scientist Dawn Mahlobo said fog was recorded on 82 days at the Kruger Mpumalanga International Airport and 85 days in Ermelo.

The department wants the first fog harvesting plant to be erected in either Piet Retief, Donkerhoek, Madadeni, Shibange or Ntunda.

“At this point in time, it is difficult to determine where exactly the fog will be harvested. The outcome of the feasibility study will determine the area suitable for fog harvesting technology,” said Mohoebi.

The bids for Mpumalanga’s pilot project closed last week Friday.

The pilot project will commence a month after a service provider is appointed.

The contractor will train community members to operate and maintain the system.

The department hopes the project will provide access to clean water and enhance local economic development with job creation in maintenance, installing, repairing fog water harvesting technology and establishment of small gardens for community.

No electricity is needed to operate the plant.

“Other communities along the escarpment will be considered if thick fog appears for 90 days or more for a few hours at a time and is accompanied by strong wind. The sites should also be at least 1km above sea level,” said Mohoebi.